1. Unit 1: Chemistry of Life
Unit 1: Biochemistry and Digestion
Unit 1: Chemistry of Life
Topic 1: Nature of Matter
Topic 2: Bonding and Properties of Water

2. Unit 1: Biochemistry and Digestion
Topic 1
The Nature of Matter

3. What are your cells made of?
Levels of Organization in Biology
Biochemistry
Anatomy
Ecology

4. SPONCH What are your cells made of? 80% Water! 20% Organic compounds
Unit 1: Biochemistry and Digestion
OBJ 1, 2
What are your cells made of?
80% Water!
20% Organic compounds
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur
Trace Elements
Iron, iodine, fluoride…..
SPONCH

5. What makes atoms of different elements different?
OBJ 3, 4
What makes atoms of different elements different?
Differing numbers of Protons, Electrons and Neutrons
Atomic number and mass number
(atoms)
(Molecules)

6. Ions and Isotopes Ion - charged atom
Obj 5
Ion - charged atom
Cation - positive, electrons lost
Anion - negative, electrons gained
Isotope - atoms of the same element but different mass
Neutron numbers different
Ex. Carbon-12 and Carbon 14

7. Bohr model of the Atom and Structural Formulas
Bohr model of Atom
Structural Formulas of Molecules
Alanine (Compound)
Chlorine (Element)
Molecules are 3D
Specific shape
Remember VSEPR
Glucose (Compound)

8. Topic 2 Bonding and Properties of Water
Unit 1: Biochemistry and Digestion
Topic 2
Bonding and Properties of Water

9. Bonding Ionic Bonds Electron transfer to fill valance shell
Unit 1: Biochemistry and Digestion
OBJ 6
Bonding
Ionic Bonds
Electron transfer to fill valance shell
Ions - charged atoms
Covalent Bonding
Electrons are shared to fill valance shells
Sharing is not always equal - Electronegativitiy
EN difference between 0 and 2 = polar covalent
EN difference 2.0 or greater = ionic

10. Unit 1: Biochemistry and Digestion
OBJ 6
Polar Molecules
Molecule acts like a magnet with positive and negative poles
Polar molecules form hydrogen bonds with each other, giving special properties
Water is involved in as many as 4 H-bonds

11. Properties of Water Polarity (within each molecule of water)
Unit 1: Biochemistry and Digestion
OBJ 7
Properties of Water
Polarity (within each molecule of water)
Uneven distribution of electrons
Greater chance of finding electrons at one end of the molecule
Due to large differences in electronegativity between the atoms
ENOxygen = 3.5
ENHydrogen = 2.1
Difference = 1.5 (strong polar covalent)
One of the few naturally occurring compounds that is liquid at the Earth’s surface

12. Obj 8/9

13. Unit 1: Biochemistry and Digestion
OBJ 8
Cohesion
Attraction between molecules of the same substance, often water
Cause molecules on surface to be drawn inward, forming a bead

14. Cohesion Surface tension allows insects and spiders walk on surface
Unit 1: Biochemistry and Digestion
OBJ 8
Cohesion
Surface tension allows insects and spiders walk on surface
Spread their weight over a large area

15. Basilisk lizard! Surface tension and rapid movement OBJ 8
Unit 1: Biochemistry and Digestion
OBJ 8
Basilisk lizard!
Surface tension and rapid movement
We would need to grow feet the size of open umbrellas and take 20 steps per second

16. Water conducting cells
Unit 1: Biochemistry and Digestion
Adhesion
OBJ 8
Attraction between molecules of different substances
Capillary action - causes water to rise in a narrow tube against force of gravity
Water conducting cells
Figure 3.3
100 µm

17. Water has a High Specific Heat
OBJ 8
Water has a High Specific Heat
4.186 J/gC
Absorbs a lot of heat
Keeps coastal climates moderate (heat sink)

18. Water has a high heat of vaporization
OBJ 8
Water has a high heat of vaporization
Sweat cools your body as it turns to vapor

19. Ice! Ice is less dense than liquid water It floats!
Unit 1: Biochemistry and Digestion
OBJ 8
Ice!
Ice is less dense than liquid water
It floats!
Density = Mass/Volume

20. Why does ice float? OBJ 8 Hydrogen bond Liquid water Ice
Unit 1: Biochemistry and Digestion
OBJ 8
Why does ice float?
Liquid water
Hydrogen bonds constantly break and re-form
Ice
Hydrogen bonds are stable
Hydrogen bond

21. “Universal solvent”
Obj 9
Substance that can dissolve many different solutes.
Water - highly polar which means it can dissolve many things
solute
solvent
solution

22. Obj 9

23. Obj 8/9

24. Unit 1: Biochemistry and Digestion
Topic 3
Basic Chemistry

25. Acids and Bases Acid – produces H+ in solution
Unit 1: Biochemistry and Digestion
OBJ 10
Acids and Bases
Acid – produces H+ in solution
Ex HCl
Base – produces OH- in solution
Ex NaOH

26. 7.4 pH scale Measure of the concentration of H+ compared to OH-
Unit 1: Biochemistry and Digestion
OBJ 10
pH scale
Measure of the concentration of H+ compared to OH-
Human blood = ??
7.4

27. pH in Biology Ecology– Acid rain
Biochemistry – acid and bases can be highly reactive with organic compounds
Anatomy
Blood is a buffer
Stomach pH

28. Activity D – Mini pH Lab Groups of 2
3 separate experiments – water, buffer, milk
10 mL of substance into beaker
Add drops NaOH
Check pH with test strips
Add your data to class data table
Record class averages
Sketch graph using class data
Clean up
Waste beaker on front table
Rinse equipment
Throw away trash

29. Chemical Reactions in Biology
Obj 11
Chemical Reactions in Biology
C6H12O6 + 6O2  6CO2 + 6H2O
Products
Reactants
Reversible reactions – Equilibrium
H+ + HCO3-
H2CO3
H2O + CO2
Dehydration synthesis and Degradation Hydrolysis